Nickel sulfide melt smelting
Nickel is a common type of metal ore, and nickel sulfide is one of the most important minerals. In order to produce nickel and its alloy, nickel sulfide needs to be smelted. Nickel sulfide smelting is a kind of process with high energy consumption, high efficiency and high technical difficulty.
The traditional smelting process of nickel sulfide is carried out in a blast furnace. In this process, iron-nickel ore is generally smelted at a high temperature in a blast furnace for about 10 hours. In this process, coke is used as reductant, soda as flux and silica or quartz as diluent. Various kinds of gases such as carbon monoxide, sulfur dioxide, hydrogen, nitrogen and other components are produced during the smelting process. The main disadvantage of this process is that the carbon monoxide produced is not only harmful to the environment but also increases the cost of subsequent processing.
Due to the high energy consumption and high cost of traditional smelting process, a process called rapid melting involving nickel sulfide is proposed. In this process, fine-grained nickel sulfide ore is used as the raw material and is preheated to a certain temperature. Then, heated to a higher temperature during the melting process, the nickel and sulfur will react completely, and the sulfur will be volatilized to form sulfur dioxide. In order to reduce the reaction time, rapid heating rate and rapid cooling rate are adopted. The main advantage of this process is that the energy consumption is lower and the process is more environmental-friendly because the highly volatile sulfur dioxide can be collected and recovered in advance.
Another advantage of rapid melting process is that it can improve the metallurgical properties of treated nickel sulfide. As the molten nickel enriched and the molten sulfur removed, a cleaner, more homogeneous and more uniform molten alloy is obtained. This can reduce the difficulty of follow-up refining and improve the quality of the final product. Moreover, because the reduction of smelting time can reduce the melting and oxidation losses of the treated ore, the melt yield of the rapid melting process is generally higher than that of the traditional process.
In summary, rapid melting process of nickel sulfide ore is superior to traditional smelting process in terms of energy consumption, cost, metallurgical properties of treated nickel sulfide, environment-friendliness and melting yield. Therefore, it is widely used in the smelting of nickel sulfide and is the current trend.
